1. Field of the Invention
The present invention relates to a charging system, and more particularly, to a charging system that can simultaneously charge multiple portable devices.
2. Description of the Prior Art
In this modern information based society, portable devices such as mobile phones, PDAs (Personal Data Assistants), CD players, portable video players (such as Digital Versatile Disc Players), hand-held computers, and notebook computers, are very common. As portable devices are becoming smaller and lighter, users are often found carrying around two or more.
In order to for these devices to function as portable, they require batteries, and typically, these batteries are rechargeable. Please refer to FIG. 1. FIG. 1 is a perspective view showing a system by which portable devices are charged according to the prior art. The portable device 10A has a charging port 12A for receiving an operating voltage carried by direct current. Two kinds of transformers, used to charge the portable device 10A, are shown. Transformer 16A has an input port 17A for receiving an alternating current 20 from a wall outlet. The transformer 16A transforms the alternating current 20 into the operating voltage of the portable device 10A and then outputs the operating voltage from an output port 14A. Similarly, an input port 19A of the transformer 18A can receive a direct current 21 from a source such as a standard automobile power point. The transformer 18A transforms the direct current into the operating voltage of the portable device 10A and then outputs the operating voltage from an output port 15A. Users can select either transformer 16A or 18A depending on the desired application. The output port of he transformer is connected to the charging port 12A of the portable device 10A and the portable device 10A becomes charged.
Portable devices have various charging port connection standards and operating voltages. Common operating voltages are 3 and 12 volts and many devices have unique charging ports. Therefore, prior art devices require specific and often unique charging assemblies. As shown in FIG. 1 each of the three portable devices (10A, 10B, and 10C) requires two charging assemblies each with a different transformer and connection. A user wanting to fully use the portability of these devices would have to carry around a total of six chargers (16A, 18A, 16B, 18B, 16C, and 18C).
As portable devices become increasingly popular, there are an ever-increasing number of places in which they can be charged. For example, automobiles provide direct current through a power point or cigarette lighter and some passenger planes provide charging sockets so that passengers can charge their portable devices while traveling. However, the prior art requires that users carry around exclusive transformers for each of the various portable devices. Not only is this an inconvenience to the user, having device specific chargers increases the costs of design and manufacture. Additionally, many of the places where a user can charge their portable devices only provide a single charging port. If a passenger of a car or airplane has more than one device that they wish to charge they must manually swap them a further inconvenience.
It is therefore a primary objective of the claimed invention to provide a charging system for portable devices that has a detachable modular design and utilizes a single power source to charge multiple portable devices requiring different operating voltages and having different connection standards.
The claimed invention, briefly summarized, discloses a charging system for charging a plurality of portable devices. Each portable device comprises a charging port for receiving a corresponding operating voltage of the portable device. The charging system comprises a plurality of transformers, at least a branch converter, and a plurality of converters. Each transformer is used to transform an input voltage into a standard voltage and output direct current from an output port. Each branch converter comprises an input port, a power conversion circuit, a transmission port, and an output port. The input port is used to receive the standard voltage outputted from the output port of the transformer. The power conversion circuit is used to transform the standard voltage into a transmission voltage and the corresponding operating voltage of the portable device. Each of the transmission voltage and the operating voltage are carried by direct current. The transmission port is used to output the transmission voltage. The output port corresponding to the charging port of the portable device is used to output the operating voltage of the portable device. The plurality of converters is used to transform the transmission voltage into a plurality of operating voltages required by the portable devices. Each converter comprises an input port corresponding to the transmission port of the branch converter for receiving the transmission voltage and an output port corresponding to the charging port of the portable device for outputting the operating voltage. When two portable devices need to be charged simultaneously, users connect the branch converter belonging to one of the portable devices to the transformer, and connect the converter belonging to another portable device to the branch converter.
It is an advantage that the claimed invention can charge many portable devices at once by using a single transformer and power supply. The claimed invention also has a modular design that can decrease production costs and makes it convenient and portable to the user.
These and other objectives of the claimed invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.